Linuxdoc Linux Questions
Click here to ask our community of linux experts!
Custom Search

4.6. IrDA and USB

The IrDA USB driver is included in recent 2.4 kernels. It's not as efficient as other FIR hardware, but at least is supported and is relatively easy to get working. Also, all the current products are based on the same hardware, and we know most of its bugs.

As far as I know the Actisys 2000U and Extended System ESI-9685 dongles seem to be based on the same hardware. Both USB dongles work fine with the Linux driver. It's possible to have multiple USB dongles in a box (for now, only up to 4).

The latest version of the driver has been tested with usb-uhci and usb-ohci. see also driver infos in src e.g. USB 2.0

There is an USB IrDA Bridge Device spec at Rev 0.9B , it's being adopted as an USB class specification. You can find it at under 0.9 Class Specification header at .

Recently a new type of USB dongle from SigmaTel has appeared on the market which is _not_ compliant with the IrDA-USB specification, and therefore doesn't work with this driver. On the other hand, SigmaTel has made available the full technical specification , so writing a driver for it is possible.

4.6.1. Environment

I have checked this chapter with this environment: ACTiSYS ACT-IR2000U FIR-USB Adapter (but it should work for any other USB dongle except the one mentioned above), Kernel 2.4.19, irda-utils 0.9.14 and Debian GNU/Linux 3.0 Woody.

4.6.2. Prerequisites

You need a kernel with appropriate IrDA and USB support and the standard entries in /etc/modprobe.conf (kernel 2.6) /etc/modules.conf (kernel 2.4) and devices in /dev/ir* as described in the chapters above. And a second IrDA device whether with Linux inside or not, e.g. a laptop, a printer or a cell phone with IrDA port.

You need a working USB controller. Check whether the appropriate module is already inserted with lsmod. If not you may insert it with modprobe usb-uhci (for Intel/Via USB controllers) or modprobe usb-ohci (for other USB controllers)

Note: this driver has NOT been tested with the usb-ehci driver (for USB 2.0 controllers). This driver WON'T WORK with the uhci driver (alternate/JE driver for Intel/Via USB controllers).


Note that there is another USB IrDA driver ( provided by the Linux USB Project) for those devices called ir-usb. This module is NOT compatible with the IrDA stack and conflicts with irda-usb. Because it always loads first, you have to remove ir-usb completely.

If you are not familiar with routing issues, I dare to recommend to shut down all external network interfaces with ifconfig during the first set up. Then check with route -n. Also netfiltering (iptables) may cause problems, so if you are not connected to a network you may disable it.

I have described the process in every detail, to make every caveat as clear as possible. The actual configuration is much shorter and easier. During configuration I will choose to open three different terminal windows to watch the log messages from different programs.

4.6.3. Plugging in the Dongle

Now plug the dongle in and check the Kernel messages with dmesg:

hub.c: USB new device connect on bus1/1, assigned device number 2
usb.c: USB device 2 (vend/prod 0x50f/0x180) is not claimed by any active driver.
usb.c: registered new driver irda-usb
IRDA-USB found at address 2, Vendor: 50f, Product: 180
irda_usb_parse_endpoints(), And our endpoints are : in=02, out=01 (64), int=03
irda_usb_init_qos(), dongle says speed=0x13E, size=0x20, window=0x2, bofs=0x4, turn=0x2
IrDA: Registered device irda1
USB IrDA support registered

If you have already some other IrDA hardware configured on the PC, the driver won't load as irda0, so to check the message log as shown above is important (the driver can manage up to 4 IrDA-USB dongles per PC, that can be increased in the source).

In this example the device is irda1. You may check this with ifconfig, too:

irda1     Link encap:IrLAP  HWaddr 2c:52:61:ec
          EtherTalk Phase 2 addr:140/191
          UP RUNNING NOARP  MTU:2048  Metric:1
          RX packets:2278 errors:0 dropped:0 overruns:0 frame:0
          TX packets:844 errors:0 dropped:0 overruns:0 carrier:0
          RX bytes:33848 (33.0 KiB)  TX bytes:15116 (14.7 KiB)

4.6.4. Attaching the Driver

Now you are ready to attach the Linux/IrDA service to the dongle With irattach irda1 -s (note the device name from the step before).

The green LED on the adapter should blink now, approximately every three seconds. And with dmesg you may see this message:

irlap_change_speed(), setting speed to 9600
irlap_recv_discovery_xid_cmd(), discovery frame to short!

Now start irdadump, you should see all IrDA devices in range. Or at least this one, here "japh" (the other IrDA device in this example is named "Olga"). For diagnostic purposes leave irdadump running in this terminal window and switch to another window for the next steps.

07:58:40.889590 xid:cmd ffffffff < 4fe026d8 S=6 s=3 (14)
07:58:40.979575 xid:cmd ffffffff < 4fe026d8 S=6 s=4 (14)
07:58:40.979679 xid:rsp 2c5261ec > 4fe026d8 S=6 s=4 japh hint=0400 [ Computer ] (20)
07:58:41.069571 xid:cmd ffffffff < 4fe026d8 S=6 s=5 (14)
07:58:41.166552 xid:cmd ffffffff < 4fe026d8 S=6 s=* Olga hint=0400 [ Computer ] (20)
07:58:43.620104 xid:cmd ffffffff < 4fe026d8 S=6 s=0 (14)
07:58:43.709078 xid:cmd ffffffff < 4fe026d8 S=6 s=1 (14)

4.6.5. Loading the IrCOMM Modules

Now load the IrCOMM modules (note this is usually done automagically by the kernel daemon kmod if you start PPP or printing via IrDA, but for the first time we do things by hand). So do modprobe ircomm and modprobe ircomm-tty .

The dmesg will show now:

IrCOMM protocol (Dag Brattli)

And with lsmod you may see:

Module                  Size  Used by    Tainted: P  
ircomm-tty             30080   0  (autoclean)
ircomm                 13164   0  (autoclean) [ircomm-tty]
irda-usb               13776   1 
irtty                   7264   0  (autoclean)
irda                  141648   1  (autoclean) [ircomm-tty ircomm irda-usb irtty]

4.6.6. Setting up a Network (PPP)

You may start pppd with commandline options, but for me it's more convenient to have a configuration file /etc/ppp/peers/irda.

connect /bin/true
kdebug 7

Some note about the configuration: Yes the device name is correct, don't choose an USB device here. If the other IrDA device is a Linux laptop you may use the same configuration file and the same PPP options, without the last line, which sets the LOCAL and REMOTE IP address. The following entries are for debugging purposes and can be commented out when everything works fine:

kdebug 7

Now start PPP with pppd call irda. For diagnostic purposes leave the messages running in this terminal window and switch to another window for the next steps.

Serial connection established.
using channel 3
Using interface ppp0
Connect: ppp0 <--> /dev/ircomm0
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x4592a46e> <pcomp> <accomp>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x4592a46e> <pcomp> <accomp>]

Now start PPP on the remote IrDA device and you should see:

sent [LCP EchoReq id=0x0 magic=0x3c8803b1]
sent [IPCP ConfReq id=0x1 <addr> <compress VJ 0f 01>]
sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x3c8803b1> <pcomp> <accomp>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x3c8803b1> <pcomp> <accomp>]
rcvd [LCP EchoReq id=0x0 magic=0xa922f0e8]
sent [LCP EchoRep id=0x0 magic=0x3c8803b1]
rcvd [IPCP ConfReq id=0x1 <addr> <compress VJ 0f 01>]
sent [IPCP ConfNak id=0x1 <addr>]
rcvd [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
sent [CCP ConfAck id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
rcvd [LCP EchoRep id=0x0 magic=0xa922f0e8]
rcvd [IPCP ConfAck id=0x1 <addr> <compress VJ 0f 01>]
rcvd [CCP ConfAck id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
Deflate (15) compression enabled
rcvd [IPCP ConfReq id=0x2 <addr> <compress VJ 0f 01>]
sent [IPCP ConfAck id=0x2 <addr> <compress VJ 0f 01>]
Cannot determine ethernet address for proxy ARP
local  IP address
remote IP address
Script /etc/ppp/ip-up started (pid 3975)
Script /etc/ppp/ip-up finished (pid 3975), status = 0x1

And in the window running irdadump you see the IrDA traffic:

08:17:11.179260 i:rsp  > ca=08 pf=1 nr=1 ns=2 LM slsap=00 dlsap=19 CONN_RSP (6)
08:17:11.199127 i:cmd  < ca=08 pf=1 nr=3 ns=1 LM slsap=00 dlsap=1d CONN_RSP (6)
08:17:11.199226 i:rsp  > ca=08 pf=1 nr=2 ns=3 LM slsap=1d dlsap=00 GET_VALUE_BY_CLASS: "IrLPT" "IrDA:IrLMP:LsapSel" (30)
08:17:11.219123 i:cmd  < ca=08 pf=1 nr=4 ns=2 LM slsap=00 dlsap=1c CONN_RSP (6)
08:17:11.219207 i:rsp  > ca=08 pf=1 nr=3 ns=4 LM slsap=1c dlsap=00 GET_VALUE_BY_CLASS: "IrDA:IrCOMM" "Parameters" (28)
08:17:11.241117 i:cmd  < ca=08 pf=1 nr=5 ns=3 LM slsap=19 dlsap=00 GET_VALUE_BY_CLASS: "IrDA:IrCOMM" "Parameters" (28)
08:17:11.241213 i:rsp  > ca=08 pf=1 nr=4 ns=5 LM slsap=00 dlsap=19 GET_VALUE_BY_CLASS: Success N/A (19)
08:17:11.259114 i:cmd  < ca=08 pf=1 nr=6 ns=4 LM slsap=00 dlsap=1d GET_VALUE_BY_CLASS: No such class (11)
08:17:11.259216 i:rsp  > ca=08 pf=1 nr=5 ns=6 LM slsap=1d dlsap=00 DISC (6)
08:17:11.280107 i:cmd  < ca=08 pf=1 nr=7 ns=5 LM slsap=00 dlsap=1c GET_VALUE_BY_CLASS: Success N/A (19)
08:17:11.280281 i:rsp  > ca=08 pf=0 nr=6 ns=7 LM slsap=1c dlsap=00 DISC (6)
08:17:11.282124 i:rsp  > ca=08 pf=1 nr=6 ns=0 LM slsap=1e dlsap=00 CONN_CMD (6)
08:17:11.299104 i:cmd  < ca=08 pf=1 nr=1 ns=6 LM slsap=19 dlsap=00 DISC (6)
08:17:11.299204 rr:rsp > ca=08 pf=1 nr=7 (2)
08:17:11.319102 i:cmd  < ca=08 pf=1 nr=1 ns=7 LM slsap=1a dlsap=00 CONN_CMD (6)
08:17:11.319209 i:rsp  > ca=08 pf=1 nr=0 ns=1 LM slsap=00 dlsap=1a CONN_RSP (6)
08:17:11.339100 i:cmd  < ca=08 pf=1 nr=2 ns=0 LM slsap=00 dlsap=1e CONN_RSP (6)
08:17:11.339197 i:rsp  > ca=08 pf=1 nr=1 ns=2 LM slsap=1e dlsap=00 GET_VALUE_BY_CLASS: "IrDA:IrCOMM" "IrDA:TinyTP:LsapSel" (37)
08:17:11.361096 i:cmd  < ca=08 pf=1 nr=3 ns=1 LM slsap=1a dlsap=00 GET_VALUE_BY_CLASS: "IrDA:IrCOMM" "IrDA:TinyTP:LsapSel" (37)
08:17:11.361191 i:rsp  > ca=08 pf=1 nr=2 ns=3 LM slsap=00 dlsap=1a GET_VALUE_BY_CLASS: Success Integer: 14 (15)
08:17:11.380092 i:cmd  < ca=08 pf=1 nr=4 ns=2 LM slsap=00 dlsap=1e GET_VALUE_BY_CLASS: Success Integer: 14 (15)
08:17:11.380214 i:rsp  > ca=08 pf=0 nr=3 ns=4 LM slsap=1e dlsap=00 DISC (6)
08:17:11.382104 i:rsp  > ca=08 pf=1 nr=3 ns=5 LM slsap=14 dlsap=14 CONN_CMD TTP credits=0(7)
08:17:11.399090 i:cmd  < ca=08 pf=1 nr=6 ns=3 LM slsap=1a dlsap=00 DISC (6)
08:17:11.399190 rr:rsp > ca=08 pf=1 nr=4 (2)
08:17:11.419082 i:cmd  < ca=08 pf=1 nr=6 ns=4 LM slsap=14 dlsap=14 CONN_CMD TTP credits=0(7)
08:17:11.419159 rr:rsp > ca=08 pf=1 nr=5 (2)
08:17:11.438080 rr:cmd < ca=08 pf=1 nr=6 (2)

Switch to another terminal and check the PPP device with ifconfig :

ppp0      Link encap:Point-to-Point Protocol
          inet addr:  P-t-P:  Mask:
          RX packets:9 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          RX bytes:318 (318.0 b)  TX bytes:708 (708.0 b)

With ps aux | grep irda you should now see these Processes:

root      3534  0.0  0.2  1272  464 ?        S    06:51   0:00 irattach irda1 -s
root      3579  0.3  0.2  1400  476 tty1     S    06:55   0:06 irdadump
root      4312  0.1  0.4  2088  948 tty2     S    07:18   0:00 pppd call irda

With route -n you may now see this PPP devices:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface UH    0      0        0 ppp0         UG    0      0        0 ppp0

And it should be possible to do a ping to the remote host:

PING ( 56 data bytes
64 bytes from icmp_seq=0 ttl=64 time=290.7 ms
64 bytes from icmp_seq=1 ttl=64 time=146.6 ms

Now you may use TCP/IP applications. For example ssh (note it will take some time to establish the connection be patient):

ssh -v USER@

4.6.7. Setting up a Printer Connection (IrLPT)

Instead of using TCP/IP connections the dongle works for printer connections, too. The device name is /dev/irlpt0. For details about IrDA printer connections see the appropriate chapter above.

4.6.8. Cleaning Up

You may now finetune your settings, e.g. to solve routing issues. It may also possible to set up higher speeds, but I haven't tried that yet. If everything works fine, you may now choose to make the configuration permanent. You may edit /etc/irda.conf and configure the system V init scripts (for IrDA, network, ..). But the way to do it right depends on your Linux distribution.

4.6.9. Remaining Problems

I encountered a strange problem. When inserting the IrDA-USB dongle, I got a slight and constant noise from the beeper.